Mattress manufacturing process and apparatus

ABSTRACT

A process and apparatus for manufacturing a mattress generally includes an automated foam layer placement apparatus for accurately securing one or more foam layers onto an innercore unit and bucket assembly.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a NON-PROVISIONAL of and claims the benefit of U.S.Application No. 62/106,947, filed Jan. 23, 2015, which is incorporatedherein by reference in its entirety.

BACKGROUND

The present disclosure generally relates to mattress manufacture, andmore particularly, to an automated foam layer placement apparatus foraccurately securing one or more foam layers onto an innercore unit andbucket assembly.

Current processes for manufacturing the mattress include numerous stepsutilizing manual labor including, among others, the process ofadhesively securing one or more foam top layers, i.e., topper layers,onto a top surface provided by innercore unit and foam encased bucketassembly. For example, as shown in prior art FIG. 1, a typical processflow 10 for placing and gluing a foam layer onto an innercore unit andfoam encased bucket assembly includes one or more operators physicallyapplying adhesive to the top surface of the innercore unit and bucketassembly. Generally, this requires a first step 12 of applying (e.g.,spraying) the adhesive onto the top surface of the assembly. Once theadhesive is applied, the one or more operators locate the desired foamlayer for placement as shown in step 13. The operators then lift andcarry the foam layer, and place the foam layer onto the innercore unitand bucket assembly as provided in step 14. As shown in step 15, theoperators then manually stretch certain portions of the foam layer so asto completely cover any underlying top surface of the innercore unit andbucket assembly. Likewise, portions of the foam layer that extend beyondthe top surface of the innercore unit and bucket assembly are lifted andrealigned with an edge of the top surface. The operators then smooth outthe surface and may push down on the foam layer to insure sufficientcontact with the applied adhesive as provided in step 16. If themattress build specifications require additional foam layers, theoperators then locate the particular foam layer and repeat the abovedescribed process as provided in step 17.

Not surprisingly, the above process has inherent variability as theseparticular steps are operator driven and manually performed. Applicationof the adhesive itself can vary across the top surface of the innercoreunit and bucket assembly since the amounts are not regulated leading tofrequent instances of inadequate adhesive as well as excessiveapplication. Inadequate glue as well as variability across the surfacecan lead to failures, which directly affect quality. Excessive adhesiveapplication, translates directly to increased costs. Moreover, the timeto perform the above described processes can be lengthy and can be asource of error when the wrong foam layer is located and placed. Stillfurther, any pressure applied by the operator is highly variable.

BRIEF SUMMARY

Disclosed herein are processes and systems for manufacturing a mattress.The process for accurately securing one or more foam layers onto aninnercore unit and bucket assembly comprises automatically sizing thefoam layer by compressing and stretching the foam layer to define anominal size; automatically applying an adhesive to a top surface of aninnercore unit and bucket assembly; automatically aligning the innercore unit and bucket assembly to a base corner datum; and automaticallylifting and placing the foam layer onto the top surface of the innercoreunit and bucket assembly using the base corner datum as a referencepoint.

An automated system for placing and securing one or more foam layersonto an innercore unit and bucket assembly is also disclosed, The systemcomprises an adhesive application station for receiving an innercoreunit and bucket assembly, the adhesive application station comprising amovable surface to support the innercore unit and bucket assembly and abridge spaced from and spanning the movable surface, the bridgecomprising one or more adhesive applicators oriented to discharge acontrolled amount of adhesive in a defined pattern onto the a surface ofthe innercore unit and bucket assembly; an innercore unit and bucketassembly alignment station comprising a movable surface and anadjustable frame assembly configured to align the innercore unit andbucket assembly to a known datum point on the movable surface; a foampick and placement station comprising a sizing table configured tocompress and stretch the one or more foam layers to a nominal size; alifting assembly comprising a plurality of lifting units spaced about anadjustable frame assembly so as to provide lifting and release of thefoam layer from the sizing table when in use, and a robotic arm coupledto the adjustable frame assembly and configured to move the adjustableframe assembly from the sizing table to the innercore unit and bucketassembly alignment station; and a compression station comprising avertically adjustable platen spaced above a movable surface.

The disclosure may be understood more readily by reference to thefollowing detailed description of the various features of the disclosureand the examples included therein.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Referring now to the figures wherein the like elements are numberedalike:

Prior Art FIG. 1 depicts an exemplary process flow for manufacture offoam topper layers onto an innercore unit and bucket assembly;

FIG. 2 illustrates an exploded perspective view of an exemplaryassembled innercore unit and bucket assembly including a foam topperlayer disposed thereon;

FIG. 3 depicts a perspective view of an apparatus for accuratelysecuring one or more foam topper layers onto an innercore unit andbucket assembly in accordance with an embodiment of the presentdisclosure;

FIG. 4 depicts a perspective top down view of an adhesive applicatorstation utilized in the apparatus of FIG. 3;

FIG. 5 depicts a side view of an exemplary glue bridge for the adhesiveapplicator station of FIG. 4;

FIG. 6 depicts partial perspective views of an innercore unit and bucketassembly alignment station utilized in the apparatus of FIG. 3;

FIG. 7 also depicts partial perspective views of an innercore unit andbucket assembly alignment station utilized in the apparatus of FIG. 3;

FIG. 8 depicts a perspective view of a foam layer sizing and robotictransfer station utilized in the apparatus of FIG. 3;

FIG. 9 depicts a perspective view of an exemplary sizing table utilizedin the foam layer sizing and robotic transfer station of FIG. 8;

FIG. 10 provides a top down view of the exemplary sizing table withpositioning of the lifting units utilized in the foam layer sizing androbotic transfer station of FIG. 8;

FIG. 11 illustrates front and rear facing perspective views of a gripperassembly for use in compressing and stretching a foam layer in the foamlayer sizing and robotic transfer station in accordance with anembodiment of the present disclosure;

FIG. 12 also illustrates front and rear facing perspective views of agripper assembly for use in compressing and stretching a foam layer inthe foam layer sizing and robotic transfer station in accordance with anembodiment of the present disclosure;

FIG. 13 illustrates a sectional view of the gripper assembly of FIGS.11-12;

FIG. 14 provides a top down view of the lifting assembly for use in thefoam layer sizing and robotic transfer station in accordance with anembodiment of the present disclosure;

FIG. 15 depicts an exemplary lifting unit for use in the liftingassembly in accordance with the present disclosure; and

FIG. 16 depicts the lifting assembly positioned to lift a foam layerfrom the sizing table of FIG. 9;

FIG. 17 depicts a perspective view and an end on view, respectively, ofa compression station utilized in the apparatus of FIG. 3;

FIG. 18 also depicts a perspective view and an end on view,respectively, of a compression station utilized in the apparatus of FIG.3; and

FIG. 19 illustrates an exemplary process flow for assembling a foamtopper layer(s) onto an innercore unit and bucket assembly in accordancewith the present disclosure.

DETAILED DESCRIPTION

Disclosed herein are an apparatus and automated process for accuratelyplacing and securing one or more foam layers onto an innercore unit andbucket assembly. FIG. 2 depicts an exemplary exploded perspective viewof an innercore unit and bucket assembly with foam topper layersgenerally designated by reference numeral 20 employed in construction ofthe mattress. The bucket 22 generally includes a planar base layer 24dimensioned to approximate the length and width dimensions of theintended mattress. The base layer 24 may consist of foam, fiber pad orit may comprise a wooden, cardboard, or plastic structure selected toprovide support to the various components that define the mattress,e.g., innercore unit, side, end rails, and the like. Depending on theinnercore unit selected and its inherent stiffness, stiffer or morecompliant base layers may be chosen. By way of example, the base layer24 may be formed of a high density polyurethane foam layer (20-170pounds-force, also referred to as the indention load deflection (ILD)),or several foam layers (20-170 pounds-force ILD each), that alone or incombination, provide a density and rigidity suitable for the intendedmattress manufacture. Other foams or fiber pads may be used. Such achoice is well within the skill of an ordinary practitioner.

An end and side rail assembly 26, which can be manufactured as a singlepiece or as multiple pieces, is affixed about the perimeter of theplanar base layer 24 to define the bucket. The end and side railassembly 26 is typically constructed from a dense natural and/orsynthetic foam material of the type commonly used in the bedding arts.The foam may be (but is not limited to) latex, polyurethane, or otherfoam products commonly known and used in the bedding and seating artsand having a suitable density. A typical density is about, but notlimited to 1.0 to 3.0 lb/ft³ and more typically 1.5 to 1.9 lb/ft³, and ahardness of 35 to 70 ILD, and more typically 40 to 65. One example ofsuch a foam is the high density polyurethane foam and is commerciallyavailable from the Foamex Corporation in Linwood, Ill. Alternatively,any foam having a relatively high indention load deflection (ILD) wouldbe satisfactory for the manufacture of the end and side rail assembly.Although a specific foam composition is described, those skilled in theart will realize that foam compositions other than one having thisspecific density and ILD can be used. For example, foams of varioustypes, densities, and ILDs may be desirable in order to provide a rangeof comfort parameters to the buyer.

The size of the end and side rail assembly 26 can vary according to themattress size and application, but each rail typically measures 3-10inches (7.5-25 cm) in thickness. The depicted end and side rails aretypically equal in width, and their length is chosen to correspond tothe length of the size of mattress desired. For a regular king size orqueen size mattress, the length of rails can be about 78.5 inches (200cm), although the length can vary to accommodate the width of the headeror footer, if the header or footer is to extend across the full width ofthe base platform 102. Similarly, the header/footer piece typically hasa thickness of about 3-10 inches (7.7-25 cm), and the width is chosen tocorrespond to the width of the size of mattress desired. In the case ofa regular king size mattress the width would be about 75.25 inches (191cm), and for a queen size mattress, the width would be about 59.25inches (151 cm), depending on how the foam rails are arranged to formthe perimeter sidewall.

The end and side rail assembly 26 can be mounted or attached to baselayer 24 by conventional means, such as (but not limited to) gluing,stapling, heat fusion or welding, or stitching.

The bucket 22 formed of the base layer 24 and end and side rail assembly26 as constructed defines a well or cavity 28. The well or cavity 28provides a space in which the innercore unit 30 can be inserted.

As noted above, the innercore unit 30 may be comprised of conventionalhelical or semi-helical coil springs and/or foam known and used in theart today. The coil springs may be open or encased in a fabric material,either individually in pockets, in groups, or in strings joined byfabric, all of which are well-known in the bedding art. For many years,one form of spring assembly construction has been known as MarshallConstruction. In Marshall Construction, individual wire coils are eachencapsulated in fabric pockets and attached together in strings whichare arranged to form a closely packed array of coils in the general sizeof the mattress. Examples of such construction are disclosed in U.S.Pat. Nos. 685,160, 4,234,983, 4,234,984, 4,439,977, 4,451,946,4,523,344, 4,578,834, 5,016,305 and 5,621,935, the disclosures of whichare incorporated herein by reference in their entireties.

Alternatively, the innercore unit may be formed of foam or a combinationof foam and coils springs. The foam, in some embodiments, can be amonolithic block of a single type of resilient foam selected from foamshaving a range of densities (themselves well-known in the art) ormultiple foam layers for supporting one or more occupants during sleep.In one embodiment, foam within the innercore unit is made of anyindustry-standard natural and/or synthetic foams, such as (but notlimited to) latex, polyurethane, or other foam products commonly knownand used in the bedding and seating arts having a density of 1.5 to 1.9lb/ft³ and 20 to 35 pounds-force ILD. Although a specific foamcomposition is described, those skilled in the art will realize thatfoam compositions other than one having this specific density and ILDcan be used. For example, foams of various types, densities, and ILDsmay be desirable in order to provide a range of comfort parameters tothe buyer.

In an alternative embodiment, the foam innercore unit may comprise oneor more horizontal layers of multiple types of foams arranged in asandwich arrangement. This sandwich of different foams, laminatedtogether, may be substituted for a homogeneous foam block of a singledensity and/or ILD.

In a further embodiment, the foam core may comprise one or more verticalregions of different foam compositions (including vertical regionshaving multiple horizontal layers), where the different foams arearranged to provide different amounts of support (also referred to as“firmness” in the art) in different regions of the sleeping surface.

Accordingly, the present disclosure is not limited to any particulartype of foam density or ILD or even to a homogenous density/ILDthroughout the foam core.

Still further, the innercore unit may comprise one or more air bladdersby themselves or in combination with coil springs, foam, or combinationsthereof.

The innercore unit and bucket assembly are then overlayed with one ormore foam topper layers 32 on the top surfaces, and the whole assemblyis encased within a ticking, often quilted, that is sewn closed aroundits periphery to a border or boxing. After assembly, the mattress can becovered by any other decorative covering or pillow-top. In the presentdisclosure, the apparatus and process are directed to precisionplacement and securement of the one or more foam top layers 32 to thetop surface of the innercore unit and bucket assembly.

The resulting mattress is not intended to be limited and may be of anytype, dimension, and/or shape. For example, the mattress may be a foammattress, a coiled mattress, a foam and coil mattress, an air mattress,combinations thereof, or the like. Typically, the mattress is square orrectangular-shaped and has a thickness ranging from about 4 inches toabout 20 inches. The length and width can vary depending on the intendedapplication and typically has a width of about 2 feet to about 7 feetand a length of about 4 feet to about 10 feet, although custom sizes mayrequire smaller or larger dimensions.

Turning now to FIG. 3, the apparatus, generally designated by referencenumeral 50, includes an adhesive applicator station 100 forautomatically applying controlled amounts of adhesive in a desiredpattern onto a top surface of an innercore unit and bucket assembly (orin the case where one foam layer has already been placed and adhesivelysecured, onto the top surface of the foam layer); an innercore unit andbucket assembly alignment station 150 for automatically aligning andaccurately defining a position thereof; automated delivery/transfer of afoam layer from an automated guide vehicle to the sizing table (notshown), a foam layer sizing and robotic transfer station 200 forautomatically delivering, locating, sizing, picking, and placing one ormore foam layers onto the innercore unit and bucket assembly; and acompression station 300 for compressing the foam layer(s) onto theinnercore unit and bucket assembly to provide consistent adhesion of thefoam layer to the underlying top surface of the innercore unit andbucket assembly.

As shown, the adhesive applicator station 100, innercore unit and bucketassembly alignment station 150, and the compression station 300 areserially aligned with one another as shown, wherein each stationincludes a movable surface (e.g., a conveyor rotatably driven by amotor) to define a travel path of the innercore unit and bucket assemblyduring alignment and as the foam layer(s) is placed thereon. However, itshould be apparent that the apparatus 50 is not intended to be limitedto the particular configuration as shown. Other variations andconfigurations will be apparent to those skilled in the art in view ofthis disclosure.

The movable surfaces of the stations, 100, 150, and 300 are generallycoplanar to each other to permit transfer into and out of the respectivestations as will be described in greater detail below. The tablessupporting the various movable surfaces may also be interconnected toprovide greater stability or may be fixedly attached to the ground. Thefoam layer sizing and robotic transfer station 200 is adjacent to theserially aligned adhesive applicator station 100, innercore unit andbucket assembly alignment station 150, and the compression station 300.In the embodiment as shown, the foam layer sizing and robotic transferstation 200 is immediately adjacent to the innercore unit and bucketassembly alignment station 150 to minimize the travel of the robot toeffect placement of the foam layer from the sizing table onto theinnercore unit and bucket assembly within the innercore unit and bucketassembly alignment station 150.

The apparatus and process is operably linked to a programmable logiccontrol system (PLC system) or serial bus system and/or manufacturingexecution solution (MES system) to plan and schedule the differentprocess steps as well as minimize and/or eliminate manual labor, whichrepresents a significant departure from prior art assembly processes.Each station is configured to communicate with the MES system, which arecommercially available from a variety of suppliers, e.g., Preactor fromSiemens AG. Designing the appropriate algorithms to perform the varioussteps to plan, schedule, operate, and control the system is well withinthe skill of those in the art. The data and inputs for operating thesystems are generally available to an operator via a computerinteractive display. The various actuators controlled by the systememployed to automate the process are not intended to be limited to anyparticular type, e.g., pneumatic, hydraulic, electrical, and the like.Suitable actuators include servomotors, stepper motors, pneumaticactuators, hydraulic actuators, and the like.

Adhesive Applicator Station

Referring now to FIG. 4, there is shown a top down view of the adhesiveapplicator station 100, which includes a table 101 having a generallyplanar support surface 102 configured to support the innercore unit andbucket assembly during the process of applying adhesive to the innercoreunit and bucket assembly. The support surface 102 can be elevatedrelative to ground and may include a movable support surface (i.e., aconveyor) for transferring the innercore unit and bucket assembly intoand out of the station. The movable support surface is not intended tobe limited to any particular type and may include a plurality of rollersand/or a rotatable belt rotatably driven by a motor for automaticallymoving the innercore unit and the bucket assembly into and/or out of theadhesive application station. Adjustment to the speed of the movablesupport surface allows for tailored feed rates to pair the adhesiveapplication with placement of the foam layer or the like, therebyproviding reproducible adhesive volume application in a desired pattern.

As shown more clearly in FIG. 5, the adhesive applicator station 100further includes a bridge 106 carried by supports 108, wherein thebridge laterally spans across the length or width dimension of thesupport surface 102. Optionally, the bridge may be mounted directly tothe underlying support surface 102. As shown, the bridge 106 generallyspans a width dimension of the support surface, which during operationextends beyond a width dimension of the innercore unit and bucketassembly. The bridge is elevated relative to the support surface andpositioned proximate to the innercore unit and bucket assembly alignmentstation 150, wherein the bridge is at a height from the support surfaceeffective to permit clearance of the innercore unit and bucket assembly,with or without additional foam layers disposed thereon. In someembodiments, the bridge may be vertically movable, which is desired forthe glue application to achieve consistent glue spray patterns. Thebridge has coupled thereto one or more adhesive applicators 110, whichmay be statically or dynamically mounted to the bridge. The adhesiveapplicators are oriented to apply a desired pattern of adhesive to a topsurface of an underlying innercore unit and bucket assembly (or foamlayer if one is already placed and secured thereto). In this manner,adhesive may be applied to the top surface as the innercore unit andbucket assembly (or foam layer) as the assembly is conveyed into andfrom the adhesive applicator station.

The adhesive applicator(s) is configured to provide a controlled amountof adhesive in a desired pattern to the top surfaces innercore unit andbucket assembly (or foam layer). In some embodiments, the adhesiveapplicator(s) may be moveable across the bridge so that application ofthe adhesive can be optimally located for each size and/or type ofinnercore unit and bucket assembly and/or foam layer as well asproviding a desired pattern of the adhesive.

In the foregoing embodiments, the application of the adhesive may beintermittent or continuous. Similarly, the adhesive may be applied tothe entire top surface or to selected portions thereof as may be desiredin some applications. In one embodiment, the adhesive applicatorincludes a plurality of nozzles in fluid communication with a source ofadhesive such as a hot melt adhesive. The adhesive applicator may becoupled to a motion detector system or sensor system (not shown) foractuating the nozzles as the innercore unit and bucket assembly istransferred into and/or out of the adhesive application station 100.Adhesive application can be triggered by the product presence sensors inconjunction with PLC logic code to ensure exact start and stop ofadhesive application for the particular mattress size. The PLC/MESsystem may be programed to adjust the adhesive application based on thetype of foam topper (density and ILD) and foam layer sequence (e.g.,third foam layer on the inner core unit and bucket assembly which isclose to the mattress surface assumes incremental movement and canrequire a different glue pattern compare to other stackedly arrangedfoam layers, e.g., additional foam layers and/or the first foam layerdisposed on the innercore unit and bucket assembly). In one embodiment,the adhesive applicator 110 is a dual pump spray system that provides ametered volume and the nozzles therein are configured to provide adesired pattern of an adhesive through the use of the programmable logiccontrol device and/or glue spray pattern code/logic. For example,actuation of the adhesive applicator can be configured to occur upondetection by the motion detector system of the leading edge of theinnercore unit and bucket assembly traveling underneath the adhesiveapplicator and discontinued upon detection of the trailing edge of thebucket. The automation provided by the adhesive applicator(s) providescontrolled adhesive application and patterning, thereby allowing forsignificantly more consistent and repeatable application of the adhesiveas compared to prior art processes. Moreover, by providing a specificpattern and volume of adhesive, significant cost savings can be realizedrelative to the prior art manual spray application of the adhesive by anoperator.

Innercore Unit and Bucket Assembly Alignment Station

The innercore unit and bucket assembly alignment station 150 shown inFIGS. 6-7 includes a support surface 152 for supporting the innercoreunit and bucket assembly during alignment as well as during foam layerplacement. The support surface 152 may include a movable support surfacefor transferring the innercore unit and bucket assembly into and out ofthe station. The movable support surface is not intended to be limitedto any particular type and may include a plurality of rollers and/or arotatable belt rotatably driven by a motor for automatically moving theinnercore unit and the bucket assembly into and/or out of the adhesiveapplication station.

The alignment station 150 further includes an adjustable rail assembly160 for aligning the innercore unit and bucket assembly to a precisereproducible location. The rail assembly generally includes tworeference rails 162, 164 that collectively define a base datum corner ofthe innercore unit and bucket assembly when seated against these rails.Reference rail 162 extends along a side of the support surface 152(i.e., the x-direction and is generally parallel to the travel path ofthe innercore unit and bucket assembly) and reference rail 164 istransverse to the support surface 152 and is positioned at the edge ofthe support surface 152 (i.e., the y-direction and is generallyperpendicular to the travel path of the innercore and bucket assembly).Reference rail 162 may be fixedly mounted to the side 167 of the supportsurface 152. Reference rail 164 is disposed at support surface end 169generally perpendicular to the travel path of the innercore unit andbucket assembly. Both rails 162, 164 may be vertically retractable withrespect to ground via an actuator controlled by the PLC system. Duringthe alignment process, reference rail 164 is in the raised position asshown and during transfer from one station to another, the rail may beretracted so as to permit the innercore unit and bucket assembly totravel unimpeded along the travel path.

The adjustable rail assembly further includes movable rails 166 and 168,wherein the rails 162, 164, 166, and 168, collectively frame theinnercore unit and bucket assembly during the alignment process withmovable rails 166 and 168 pushing the innercore unit and bucket assemblyagainst the reference rails, thereby establishing a base datum referenceindicative of the exact position and orientation of the innercore unitand bucket assembly. Movable rail 166 is positioned parallel to thetravel path of the innercore unit and bucket assembly and is configuredto move in the y-direction so as to compress against a sidewall of theinnercore unit and bucket assembly when in use and movable rail 168 isconfigured to push against a sidewall of the innercore unit and bucketassembly in the x-direction. Each of the rails 162, 164, 166, and 168includes a planar surface perpendicular to the support surface. In thismanner, during alignment the movable rails 166, 168 serve to push theinnercore unit and bucket assembly against reference rails 162, 164 suchthat a corner of the innercore unit and bucket assembly is seatedagainst reference rails 162, 164 at a precise, reproducible location andorientation.

Movable rail 166 is movably disposed on a support surface 170 that isadjacent and coplanar to end 171 of the support surface 152. Supportsurface 170 includes one or more track guides 174 that are generallyperpendicular to the travel path of the innercore unit and bucketassembly. An arm 176 is attached at one end to a back side of the rail166 and at the other end movably coupled to the track guide. Theparticular numbers of arms attached to the rail 166, three of which areshown, are not intended to be limited. At least one arm is operablylinked to rail 166. Likewise, the number of track guides is not intendedto be limited and will generally correspond to the number of arms. Anactuator controlled by the PLC system is operably linked to the arm toselectively move rail 166 along the track guide 174.

Movable rail 168 is attached to a hinge 178 at one end 179 and to aretractable arm 180 at about the other end 182. The retractable arm 180provides rotation about an axis of the hinge 178 such that when in usethe rail 168 is positioned to be parallel to a sidewall of the innercoreunit and bucket assembly and when not in use the rail is retracted awayfrom the sidewall. As shown, retraction of the arm 180 in the directionshown by arrow 182 swings the rail 168 out of the travel path of theinnercore unit and bucket assembly. The hinge 178 (and rail 168) ismovably coupled to guide rails 176 to effect linear movement of the railalong the travel path if the innercore unit and bucket assembly. Whenthe arm is extended, travel of the rail 168 along the guide rails 176permits the rail 168 to push against a sidewall of the innercore unitand bucket assembly. Optionally, the movable rail may further include astop (not shown) for receiving the rail when retracted. The stop may bemagnetic and may include a recess for receiving the rail. One or moreactuators, e.g., servomotors, two of which are shown, are operablylinked to the rail 168 to provide extension and retraction of rail aswell as to movement of the rail along the guide rails.

Foam Layer Sizing and Robotic Transfer Station

Turning now to FIG. 8, there is shown the foam layer sizing and robotictransfer station 200, which generally includes a robotic liftingassembly 202 and a foam layer sizing table 204. The robotic liftingassembly 202 moves in response to command signals to lift a nominallysized foam layer from the sizing table 204 and precisely place the foamlayer onto the innercore unit and bucket assembly. The robotic liftingassembly 202 generally includes a multi-axis functional robot 205 and alifting assembly 206 attached to an arm 207 of the multi-axis functionalrobot. The robot itself is not intended to be limited and iscommercially available from numerous sources. An exemplary industrialrobot for picking and placing the foam layer is commercially availablefrom ABB Ltd.

As shown in FIGS. 9-10, the sizing table 204 includes a generally planarsurface 250 for supporting the foam layer during the sizing process. Theplanar surface 250 may include a plurality of perforations 252 extendingthrough the surface. The sizing table 204 further includes an adjustablerail assembly 254 shown more clearly in FIG. 10 for sizing the foamlayer to a nominal size and providing a precise reproducible location tothe apparatus. As used herein, the term nominal size is to be accordedits usual and customary meaning. In general, nominal size refers to astandardized dimension specific to the intended mattress dimension,e.g., twin, queen and the like. The nominally sized foam layer willgenerally be sized to match the length and width dimensions of theinnercore unit and bucket assembly (or foam layer disposed thereon) towhich the nominally sized foam layer is to be attached. The adjustablerail assembly 254 is configured to frame the foam layer as shown in FIG.9 and automatically compress the foam layer to less than nominal sizefollowed by stretching of the foam layer to the nominal size defined bythe programmed specification for the particular foam layer, which isthen lifted and subsequently placed on the innercore unit and bucketassembly via the robotic lifting assembly 202. As will be discussed ingreater detail below, the adjustable rail assembly 254 provides a basedatum corner 256 for the foam layer, which is then matched with the basedatum corner of the aligned innercore unit and bucket assembly toprovide precise placement and orientation of the foam layer onto theinnercore unit and bucket assembly.

The adjustable rail assembly 254 generally includes two reference rails258, 260 adjustably positioned on the sizing table 204 that generallyintersect at one end at a right angle on the table at a known locationso as to collectively define the base datum corner 256 for the foamlayer when seated against these rails. Reference rail generally 258generally corresponds to a width dimension of the foam layer andreference rail 260 generally corresponds to a length dimension of thefoam layer.

The adjustable rail assembly further includes movable rails 262 and 264,wherein the rails 258, 260, 262, and 264 collectively frame the foamlayer during the sizing process with the movable rails 262 and 264aligning the foam layer, which is then compressed by the rails 258, 260,262, and 264. The rails may be of unitary construction or may comprisesegments of equal or differing lengths, wherein each segment may beindependently controlled by an actuator, e.g., a pneumatic actuator.

Movable rail 262 is positioned parallel to reference rail 258 andmovable rail 264 is positioned parallel to reference rail 260 so as todefine the adjustable rail assembly 254. Each of the rails 258, 260,262, and 264 includes a planar surface perpendicular to surface 250. Inthis manner, during sizing the rails 258, 260, 262, 264 serve tocompress the foam layer against the respective opposing rail.

The surface 250 further includes one or more track guides 270 that aregenerally perpendicular to rails 258, 260, 262, and 264. The rails areoperably coupled to the track guides 270 via an arm 272 attached at oneend to a back side of the rails and at the other end movably coupled tothe track guide. The particular numbers of arms attached to the railsare not intended to be limited. At least one arm is operably linked tothe rail. Likewise, the number of track guides is not intended to belimited and will generally correspond to the number of arms. An actuatorsuch as a servomotor controlled by the PLC system is operably linked tothe arms to selectively and precisely move the rails along thecorresponding track guide 270. Movable rails 262 and 264 include longertrack guides to accommodate different size foam layers whereas rails 258and 260 include shorter track guides to provide compression of the foamlayer during the sizing process.

Each of the rails 258, 260, 262, and 264 further includes a gripperassembly for clamping onto the foam layer during the stretching step ofthe sizing process. As noted above, the foam layer is first compressedagainst the rails to less than nominal size. During the stretching step,the gripper assemblies disposed on the rails 258, 260, 262, 264 areactuated to clamp downward onto the foam layer and rails 262, 264 arethen moved to a predefined position. The movement of rails 262, 264 tothe predefined position stretches the foam layer to its nominal size asdefined by the foam layer specification. The gripper assemblies 280 aregenerally pivotably coupled to and spaced about the rails to providecontrolled gripping of the foam at the edge and stretching.

The particular gripper assemblies 280 are not intended to be limited. Anexemplary gripper assembly is shown in FIGS. 11-13, wherein the gripperassembly 280 generally includes an actuator 282, e.g., a linear actuatoror the like, that is coupled at one end to bar 284 and at the other endto a second actuator 285 disposed underneath the table 204 via a link286 engaged within track guide 270. Actuation of the second actuatoreffects precision movement of the rail e.g., rail 258, across thesurface 252 of the sizing table 204. The bar 284 is pivotably coupled tothe rail and attached to a pivotably movable upper plate 288. The railfurther includes a lower plate 290 upon which an outer periphery of thefoam layer is generally disposed on after the foam layer is placed onthe sizing table and compressed. Actuation of the actuator 284 pivotablylowers the movable upper plate 288 so as to sandwich the outer peripheryof the foam layer between the movable upper plate 288 and the lowerplate 290. Subsequent movement of the second actuator outwardly from thefoam layer causes the rails to stretch the foam layer. Movement acrossthe table is carefully controlled so that the foam layer is stretched toits nominal size.

In one embodiment, sensors may be located on the rails to assist inaligning the gripper assemblies to the edges of the foam layer.Servomotors may be employed to move the rails to the programmedposition, e.g., moves the rails including the gripper assemblies tocontact foam layer

As shown more clearly in FIG. 14, the lifting assembly 206 includes aframe 208 with a primary beam 210 bisecting the frame 208 at about amidpoint. Secondary beams 212 are coupled to the beam 210 and/or theframe 206 to define a rectangularly shaped portion of the liftingassembly having attached thereto statically positioned lifting units 216in a spaced arrangement about the rectangularly shaped portion, whereinthe rectangularly shaped portion overlays a major portion of anunderlying foam layer. The lifting assembly 206 further includes supportbeams 220 for supporting movable beams 222, 224, and 226 mountedthereto. Each movable beam 222, 224, and 226 includes additional liftingunits 216 spacedly arranged on the beams. In some embodiments, theposition of the lifting units 216 may be adjustable on the rail. Theposition of these movable beams 222, 224, and 226 can be selected andoptimized based on the dimensions of the foam layer to be liftedcorresponding to the mattress size. For example, movable beam 222 can beselectively moved to accommodate the manufacture of mattresses havingvarious lengths e.g., standard, long, extra-long, etc. whereas movablebeams 224 and 226 can be selectively moved to accommodate themanufacture of mattresses having various widths, e.g., twin, full,queen, king, etc. The movable beams are generally positioned to overlayan edge of the underlying foam layer that is outside the area overlayedby the statically positioned rectangular shaped portion discussed above.The position of the movable beams can be programmed in the PLC system.Precise movement of the rails can be provided by precision ball bearingslides or the like. An attachment plate 214 is centrally located on theframe and provides the means for attaching the arm to the liftingassembly.

As shown more clearly in FIG. 15, each one of the lifting units 216generally includes a head 240 that supports two slides 242, 244, each ofwhich is provided with one or more retractable angled needles 246 (shownextended from the head). The needles on one slide face towards theneedles of the other slide, sloping one towards the others. The needlesare at an angle relative to a foam layer of about 30 (150) to about 60(120) degrees in most embodiments, although angles greater or less thanthis range can be used. In one embodiment, the needles are at an angleof 45 (135) degrees. Moreover, the needles from the respective slidesare spaced by a gap 248 such that the needles from the opposing slidesoverlap when extended into the foam layer.

Both of the slides, and with them the needles that are fixed to them,are controlled and movable in opposite directions between an idleposition, in which the needles on one slide are retracted and are at adistance from those on the other slide, and an active position, in whichthe needles of the two slides move forward, cross each other and slopingpenetrate into the element to be picked up and, with the help of a flathead, they are able to gather it and transfer it according torequirements. An exemplary needle gripper is commercially available fromSchmalz Inc. Exemplary needle grippers are disclosed in U.S. Pat. No.8,104,807, incorporated herein by reference in its entirety and arecommercially available from Schmalz, Inc.

FIG. 16 depicts the lifting assembly 206 positioned to lift an exemplaryunderlying foam layer 500 that has previously been compressed andstretched to a nominal size. The movable beams 222 and 224 are optimallypositioned such that lift units 216 are at positions disposed over aperipheral edge of the foam layer as well as spacedly and uniformlyarranged over an interior region of the foam layer so as to lift thefoam layer and maintain its nominal size. In the embodiment shown,movable beam 226 is not needed to lift this particular sized foam layerand is positioned such that the lifting units disposed thereon do notoverlay the foam layer.

During operation, the sizing table 204 (FIG. 9) first receives a foamlayer from a delivery system, e.g., manually placed by an operator orthrough an automated guide vehicle or robotic assist via grippers, orthe like. The movable rail sections on the sizing table 204 areactivated to match the size of the foam layer being sized. Theactuators, e.g., servomotors, are configured and programmed to move therails until it contacts the foam layer. The adjustable rail assembly 254holds the foam as it is transported to the base corner datum. Thegripping assemblies 280 are then activated and the foam layer isstretched to its nominal size, which matches the length and widthdimensions of the innercore unit and bucket assembly. The liftingassembly 206 is then robotically lowered onto the foam layer and thelifting units incorporating needles are activated to engage the foamlayer. The foam layer at its nominal size is then placed onto theinnercore unit and bucket assembly using the base corner datums as areference point to provide precise placement of the foam layer.

Advantageously, the sizing function may incorporate variable compressionforces, variable stretching forces, and clamping based on the foam typewith real time adjustments to achieve the intended functional valuedesired. Consequently, sizing of the foam layer will reduce processvariability by providing consistency in terms of the size and preciseplacement of the foam layer onto the previously aligned and knownposition of the innercore unit and bucket assembly.

Compression Station

As shown in FIGS. 17-18, the compression station 300 generally includesa support surface 302 coplanar and serially connected to the supportsurface of the alignment station 150. The support surface 302 mayinclude a movable support surface for transferring the innercore unitand bucket assembly with the foam layer(s) thereon into and out of thestation. The movable support surface is not intended to be limited toany particular type and may include a plurality of rollers and/or arotatable belt rotatably driven by a motor for automatically moving theinnercore unit and the bucket assembly into and/or out of the adhesiveapplication station.

The compression station 300 further includes a vertically movable platen304 disposed above the support surface. The platen 304 may be driven byactuators (not shown), e.g., pneumatic actuators, hydraulic actuators,or the like that move the platen vertically upward and downward suchthat when the innercore unit and bucket assembly having the foam layersdisposed therein are transferred to the compression station, the platenis lowered to compress the assembly. The compression of the assemblyprovides a predetermined and programmed pressure on the assembly toprovide consistent and uniform downward pressure across the surface ofuppermost foam layer, which serves to maximize contact of the adhesivebetween the various layers, thereby minimizing the amount of adhesiveused compared to the prior art as well as providing reproducibility withregard to adhesive strength.

The platen 304 has a substantially planar surface that contacts thesurface of the uppermost foam layer. The platen is generally dimensionedsuch that the substantially planar surface can be configured to providea constant pressure across the entire surface of whatever size foamlayer the platen contacts. As such, the platen is generally dimensionedto be larger than the largest size mattress being assembled. Thesubstantially planar surface may be formed of a single piececonstruction or may be formed of plates. In some embodiments, theindividual plates may be independently actuatable so as to exertdiffering pressures as may be desired in some applications.

Programmable Logic Control and Manufacturing Execution System

As noted above, the apparatus can be fully automated via a programmablelogic control and/or manufacturing execution solution system (i.e., thePLC/MES system) using a radio frequency identification tag (RFID) forcomponent identification. By way of example, RFID tags may be affixed tothe innercore unit and bucket assembly and/or foam layers and/or storageareas corresponding to the particular component for wireless recognitionby the PLC/MES system. In this manner, orders can be managed andscheduled from the PLC/MES system. Still further, each of the varioussteps for placing and securing the foam layers onto the innercore unitand bucket assembly can be fully automated via the programmable logiccontrol/manufacturing execution solution system, thereby requiring nooperator interaction. Use of RFID tags for component identificationenhances changeovers and allows for simple correction for variationbetween different innercore and bucket assembly types as well asdifferent foam layer types.

The Process

Turning now to FIG. 19, the process 400 of operating the apparatus 50generally includes a first step 402 of delivering a foam layer to therobotic foam layer sizing and robotic transfer station 200. This step isautomatically performed. For example, an operator manually places thefoam on the automated guide vehicle which can be programmed toautomatically locate and transfer a desired foam layer to the sizing andtransfer station. The foam layer is then sized in the sizing station,which first compresses and then stretches the foam layer to a nominalsize as shown in step 404.

Prior to or simultaneously with the location and sizing of the foamlayer, an innercore and bucket assembly is provided to the adhesiveapplication station 100 as shown in step 406. In one embodiment, theinnercore unit and bucket assembly can be directly fed from an innercoreunit and bucket assembly apparatus. An exemplary innercore unit andbucket assembly apparatus is disclosed in U.S. patent application Ser.No. 14/481,419 entitled: Mattress Manufacturing Process and Apparatus toMichael DiMarco and filed on Sep. 9, 2014, incorporated herein byreference in its entirety. For example, the innercore unit and bucketassembly can be transferred to the conveyor of the adhesive applicationstation where a predetermined pattern and volume of adhesive is thenapplied to the top surface. The innercore unit and bucket assembly withthe applied adhesive is then transferred to the alignment station 150for alignment. All four sides are aligned as shown in step 408, whereinthe coordinates are provided to the programmable logic control system.

The foam layer at the nominal size is then picked up from the foam layersizing and robotic transfer station 200 and placed on the top surface ofthe aligned inner core unit and bucket assembly as shown in step 410. Inthis manner, the foam layer is precisely placed on the top surface ofthe innercore unit and bucket assembly (or previously deposited foamlayer) and onto a controlled amount and defined pattern of adhesive. Theprocess is then repeated until all foam layers for the mattress designbuild are placed as provided in step 412.

Subsequent to foam placement on the innercore and bucket assembly (orpreviously deposited foam layer), the assembly is transferred to thecompression station, wherein downward pressure is applied onto theassembly to insure maximum and consistent adhesion of the foam layer tothe innercore unit and bucket assembly. In situations where multiplefoam layers are placed, the programmable logic control system may beprogrammed to provide the step of compression after each foam layer isadhesively placed, after selected foam layers are placed, or after allof the layers are placed. The system provides latitude as to when thismay occur.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to make and use the invention. The patentable scope of the inventionis defined by the claims, and may include other examples that occur tothose skilled in the art. Such other examples are intended to be withinthe scope of the claims if they have structural elements that do notdiffer from the literal language of the claims, or if they includeequivalent structural elements with insubstantial differences from theliteral languages of the claims.

What is claimed is:
 1. An innercore unit and bucket assembly alignmentapparatus, comprising a support comprising a planar conveying surfacefor supporting and automatically moving the innercore unit and bucketassembly from an entry point to an exit point; a longitudinal referencerail parallel to and fixedly coupled to an edge of the conveyingsurface; a retractable transverse reference rail coupled to the exitpoint forming a right angle with the longitudinal reference rail duringalignment when in use; a longitudinal positioning rail in movablecommunication with and coupled to the support configured to push theinnercore unit and bucket assembly against the longitudinal referencerail; and a transverse positioning rail in movable communication withand coupled to the support configured to push the innercore unit andbucket assembly against the retractable transverse reference rail whilemaintaining sliding engagement with the longitudinal reference rail,wherein the longitudinal reference rail, the retractable transversereference rail, and the longitudinal reference rail each comprise acontact surface perpendicular to the planar conveying surface, whereineach contact surface is configured to contact a respective side of theinnercore unit and bucket assembly during alignment.
 2. The innercoreunit and bucket assembly alignment apparatus of claim 1, wherein thelongitudinal positioning rail is movably disposed on a support surfacethat is adjacent and coplanar to the planar conveying surface, whereinthe longitudinal positioning rail extends onto the planar conveyingsurface during alignment via arms movably coupled to the adjacentsupport surface.
 3. The innercore unit and bucket assembly alignmentapparatus of claim 2, wherein the adjacent support surface comprises atleast one track guide, wherein the arms are coupled to the at least onetrack guide via an actuator at one end and to the longitudinalpositioning rail at another end.
 4. The innercore unit and bucketassembly alignment apparatus of claim 3, wherein the actuator iscontrolled by a programmable logic control system to selectively movethe longitudinal positioning rail along the track guide.
 5. Theinnercore unit and bucket assembly alignment apparatus of claim 1,wherein the transverse reference rail at the exit point is retractablycoupled to the support.
 6. The innercore unit and bucket assemblyalignment apparatus of claim 1, wherein a base datum corner is definedwhen the innercore unit and bucket assembly is seated against thelongitudinal reference rail and the transverse reference railcorresponding to a known position of the innercore unit and bucketassembly.
 7. The innercore unit and bucket assembly alignment apparatusof claim 1, wherein the transverse positioning rail in movablecommunication with the support is pivotably coupled to the support atthe edge of the conveying surface via a motor actuated arm coupledthereto.
 8. The innercore unit and bucket assembly alignment apparatusof claim 1, wherein the transverse reference rail is coupled to anactuator configured to raise the transverse reference rail above theplanar conveying surface during alignment and retract the transversereference rail below the planar conveying surface to permit theinnercore unit and bucket assembly to travel unimpeded along a travelpath defined by the planar conveying surface.